Since it has been reported that PRR activation promotes the production of profibrotic factors through activating ERK signaling, we examined the effect of HRP on high glucose-induced phosphorylation of ERK1/2 and TGF-β1 expression, one of the most important fibrotic factors in DN (Nguyen et al., 2002). The gene discussed is ATP6AP2; the disease is liver dysplastic nodule.